This is a rare disease, which is inherited. It is not contagious, but it is fatal and cannot be treated. It affects the nervous system including the brain. The likelihood of a Border Collie developing the disease is very small as can be seen by the number of cases identified since 1980, when the first case was diagnosed. There have been less than 30 cases notified, indicating that the incidence of CL is less than 1 in 1800 pure bred Border Collies.

DNA Research has identified the gene for the identical disease, which occurs in humans and is known as Battens Disease. When this gene is identified in Border Collies, we will be able to eliminate the disease from the breed in one or two generations.

The CL Sub-Committee of The Border Collie Club of NSW Inc investigates the incidence of the disease and sister clubs are informed when affected cases are notified.

The names and pedigrees of proven identified carriers are periodically published (with permission from the owners of the animals) to improve the knowledge of inheritance.

CL has been found in other breeds of dogs ie Cocker Spaniels, Dachschunds, English Setters, Miniature Schnauzers, Rough Collies, and Salukis as well as in Devon Cattle, South Hampshire Sheep and in Siamese Cats

The occurrence of CL in Border Collies is not the fault of any one person or group. The defective gene was carried by an imported dog at a time when the disease was unidentified. Since then, CL has occurred sporadically, as most Australian bred Border Collies are descended from that dog. Therefore, no breeder can be 100% sure that their stock does not carry the defective gene.

Line breeding increases the risk of producing genetic defects and diseases.

Symptoms and Diagnosis of CL (Storage Disease)

Affected animals appear normal until aged approx 15 months. From that age any or all of the following signs may be noted:

• Unreasonable apprehension or fear of familiar objects/surroundings

• sight disturbance

• abnormal gait – is unsteady on feet and has difficulty in climbing or jumping, tends to prop or goose step,

• demented behaviour, mania, hyperactivity, rage, disorientation, fixations

• loss of toilet training,

• strange or abnormal behaviour.

The progress and effect of the symptoms will steadily continue to deteriorate and medication cannot improve the condition. Affected animals have all been euthanased by the age of 3½  years. CL symptoms can be confused with other brain disorders.

To date, there is no test available to identify carriers of the defective gene. Suspected cases can be confirmed by brain biopsy from the age of 7 months. A post mortem will also give an accurate diagnosis.

If you are concerned that your dog may have CL, please contact the CL Sub Committee or Dr Alan Wilton, University of NSW School of Biochemistry.

GENETIC INHERITANCE of CL

Genetically the dog/bitch falls into one of three categories:

• Clear: Has not inherited a defective gene, ie is totally free of the disease.
• Carrier: Has inherited a defective gene, ie shows no symptoms, but may pass the gene to its offspring.
• Affected: Has inherited the defective gene from both parents and has or will develop the disease.

Important points to remember are:-

• All progeny of affected animals must be either carriers or affected.
• To produce an affected animal, both parents must be either carriers or affected.

The following diagrams show the mating possibilities using the mathematical ratios of Mendel.

These indicate the probable inheritance of CL for any individual puppy from such matings

If you or your vet suspects that your dog may have CL, please contact the breed and/or a member of Border Collie Club in your state.  Complete confidentiality must be observed by the CL subcommittee members, and we can advise and help you where necessary. Suspected Cases can be referred to:

 

Prof Virginia Studdart

University of Melbourne

School of Veterinary Science

Werribee Vic 3030

Ph (03) 9741 3500.

 

Dr Wilton and Scott Melville are conducting Genetic research to develop a DNA test and can be contacted at:

 

School of Biochemistry and Molecular Genetics,

Faculty of Life Sciences,

University of NSW,

Sydney 2052, Australia

Phone: +61 2 9385 1674  FAX: +61 2 9385 1483

EMAIL: scott@unsw.edu.au

If a suspected case is to be euthanased, please contact Dr Alan Wilton or Scott Melville prior to this being carried out, to arrange for the collection of blood and tissue samples for the CL DNA bank.

Phone:   02  9385 2019

Fax:  02 9385 1483

Email:  a.wilton@unsw.edu.au